The manuals call those an "adjuster pinion". They are present on the rear of 1 ton, 1 1/2 ton and 2 ton trucks with Huck brakes. They work great and are easier to use than a screwdriver through the slots, until they don't work due to corrosion. If they are difficult to turn, cease your efforts and pull the drum, so that you can free them and the cylinder ends up. The pinion itself is soft metal and the bolt shaft will just turn the slotted hole into a round hole. To re-attach the pinion to the bolt shaft the manual says to peen over the end while in place. It might be easier to weld it to the bolt in a spot or two, but don't weld it to the backing plate! After proper adjusting your brakes you will find that you will have a firm pedal and the truck will stop quite well.
Kent
Last edited by Lightholder's Dad; 01/23/2021 3:45 PM.
